A new Trojan horse seeks out and wipes movies and MP3 music tracks that it believes are illegally distributing via file-sharing networks.

The Troj/Erazer-A Trojan horse scours folders used for peer-to-peer file-sharing peer-to-peer for AVI, MP3, MPEG, WMV, GIF, ZIP and other files. If files are found by the Trojan it wipes them, and plants a copy of itself in the folder using tempting names such as game.exe, goporn.exe, nero7.exe and officexpcrack.exe.

The Erazer Trojan horse also attempts to terminate a number of different security-related applications, which may assist hackers in gaining access to a compromised computer.

"The Erazer Trojan is a vigilante worthy of a Charles Bronson movie, taking the law into its own hands. However, it's perfectly possible for the Trojan to aim poorly and wipe out innocent files too," said Graham Cluley, senior technology consultant for Sophos. "The Erazer Trojan targets internet users it believes are involved in piracy, but fails to discriminate between the true criminals and those who may have MP3 music files or home movies that they have created themselves. Malware is not the way to fight internet piracy."